Traffic control algorithm for optical packet router using electrical edge routers as shared buffers

An algorithm using electrical edge routers as shared buffers is studied as a packet collision avoidance method in optical packet routers that switch variable-length packets of light. In this algorithm, packets in contention on the output lines of an optical packet router are switched to an electrical edge router placed at the same location, electrically converted temporarily, and buffered. If few packets are electrically processed by buffering compared to the total, since most of the packets are transferred as light, the optical packet router can have an extremely large processing capacity with respect to the limit of the processing capacity of the electrical router. In this paper, we propose an edge traffic control algorithm to improve the performance of the optical packet router. The edge router used as a buffer is positioned at the same location as the optical router. The traffic transmitted from this location can be controlled in response to the state of the optical router. In the proposed control algorithm, transmissions from the edge are controlled when the output lines of the optical router are congested to ease congestion. The performance of this optical packet router is improved by this control, and the application range of the optical packet router satisfying fixed performance conditions clearly expands. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 88(12): 61–70, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20190